Yogurt making at home is a tedious process comprising of multiple preparation steps starting from slowly boiling milk to approximately 180 Fahrenheit while stirring continuously for 20 minutes or more to break down milk proteins and prevent clumping. Subsequently, milk is allowed to cool down to fermentation temperature of around 110 F, at which point culture is stirred into the milk. The milk and culture mixture is then stored in an insulated constant temperature environment for a fixed amount of time which can vary from 6 to 12 hours or more. After yogurt is thus fermented for the stipulated time, it needs to be transferred to refrigerator otherwise it may turn sour. Furthermore, to make a thicker yogurt another manual step of straining to separate liquid whey may be required. Thus, all these steps require careful human attention to achieve good results.
Existing yogurt makers in the market mostly help in the last phase of the yogurt making process by providing a constant temperature environment for optimal fermentation. However, there is no single device which can handle all the steps of yogurt making.
Current techniques of home yogurt making require several different devices. One cooking device (e.g., a pot or other cooking appliance) is needed to boil milk. A separate culture device is needed for yogurt culture to be kept at an appropriate temperature until combined with the milk. Otherwise, in an appliance which will also boil the milk, the temperature will reach high levels and the yogurt culture can potentially be destroyed and consequentially prevent fermentation. A mixer device is needed to combine the yogurt culture and milk. If skin forms on the milk surface, it can cause boil-over and also give a bad texture to the yogurt. Yet another refrigeration device is needed to refrigerate fermented yogurt. Each device functionality places a significant load on the power supply (e.g., a cooking device, a heating device, a mixer device, and a refrigeration device. Further, a device which handles milk can be hard to wash and may develop smell issues over time for any parts exposed to milk.
It is highly desirable to overcome shortcomings of the existing multitude of yogurt maker devices and to overcome all the challenges of integrating multiple steps of yogurt making. It is further desirable for a robust autonomous cooking device to automatically prepare yogurt in a single process from a user perspective.